Suction apparatus for picking up various shaped articles, especially paper rolls



Sept. 8, 1964 J. E. OLSON 3,147,872

SUCTION APPARATUS FOR PICKING UP VARIOUS SHAPED ARTICLES, ESPECIALLYPAPER ROLLS Filed Oct. 24. 1960 7 Sheets-Sheet 1 INVENTOR. John E. OlsonBuckhorn, Chearham '8 Blore ATTORNEYS P 3, 1964 J. E. OLSON 47,

SUCTION APPARATUS FOR PICKING UP VARIOUS SHAPED ARTICLES, ESPECIALLYPAPER ROLLS Filed Oct. 24, 1960 7 Sheets-Sheet 2 o o o 3 o g; a o o Ifig W a 263 w o O 3i H O 233 e l T 0 1 2 225 $1 2 W o w 22\ 6 l am 2'3ze5 I 2O 5 I65 20| 269 |s3 3 -|6? -ls3 o 0 o $0 j P79. 4 INVENTOR.

I John E. Olson Buckhorn, Cheatham 8 Blore ATTORNEYS Sept. 8, 19643,147,872

- J. E. OLSON SUCTION APPARATUS FOR'PICKING UP VARIOUS SHAPED ARTICLES,ESPECIALLY PAPER ROLLS Filed Oct. 24. 1960 7 Sheets-Sheet s Fly. 6

(ON TRUCK) I63 H9- M 9 INVENTOR.

John E. Olson Buckhorn, Cheatham 8 Blore ATTORNEYS Sept. 8, 1964 J. E.OLSON 3,147,372

SUCTION APPARATUS FOR PICKING UP VARIOUS SHAPED ARTICLES, ESPECIALLYPAPER ROLLS Filed Oct. 24. 1960 '7 Sheets-Sheet 4 :1 uuuuc 287/ nu: 335Jun 300%) 0 333 l2 i I INVENTOR.

John E. Olson m Buckhorn, Cheatham 8 Blore H ATTORNEYS Sept. 8, 1964OLSON 3,147,872

SUCTION APPARATUS FOR PICKING UP VARIOUS SHAPED ARTICLES, ESPECIALLYPAPER ROLLS Filed Oct. 24. 1960 7 Sheets-Sheet 6 TO VACUUM PUMP IIIVACUUM ON 25 22 3s? gai 387 V TO VACUUM OFF PUMP Fig. 23

VACUUM Fly. 24

INVENTOR,

John E. Olson BY Buckhorn, Cheatham 8 Blore ATTORNEYS United StatesPatent 3,147,872 SUCTION APPARATUS FOR PICKING UP VARIOUS SHAPEDARTICLES, ESPECIALLY PAPER ROLLS John E. Olson, Portland, 0reg.,assignor to Hyster Company, Portland, 0reg., a corporation of NevadaFiled Oct. 24, 1960, Ser. No. 64,639 3 Claims. (Cl. 214-652) Thisinvention relates to a suction apparatus and method for picking uparticles ofv commerce, particularly paper rolls, such as heavy rolls ofnewsprint paper, kraft paper and the like.

In the past, it has been the practice to pick up a paper roll by a clampdevice on the front of a lift truck. Such a device is complicated andquite expensive. I

It is a main object of the present invention to provide a method ofpicking up a paper roll which makes use of subatmospheric pressure, andto provide a simple and relatively inexpensive apparatus by which themethod can be carried out.

Despite the fact that it is quite old to handle and pick up rigidarticles of commerce by means of suction heads, prior to the presentinvention, no one apparently thought it possible to pick up a heavy rollof paper by means of a suction head means. Apparently, it was thoughtobvious that the outer loop of paper would simply tear off. Also,apparently the end edges of the roll are not normally sealed andobviously air could enter, it was thought, between the loop and theremainder of the roll to make lifting the roll an impossibility.

Sometimes a roll of paper is enclosed in a wrapper. It was apparentlyalso thought obvious that such a wrapper was not strong enough tosupport the roll or enable it to be lifted, and in addition the wrapperfrequently was punctured and it was apparently thought that this wouldmake it impossible to lift the roll. Still further, it is sometimes thepractice in the industry to fasten the outer end of the paper of a rollin place by one or two adhesive pieces, leaving the remainder of the endedge unsecured. Obviously, it was thought, air could readily enterbetween such unsecured portions and the next inner loop making suctionlifting possible. Also, sometimes, the outer end becomes unsecured, andwhile this does not prevent handling by a clamp, apparently it wasthought that this would prevent the roll being lifted by any suctionmeans.

I have discovered that a roll of paper can be picked up by a suctionhead means provided only that the outer loop or wrapper at the locationof the head tightly lays against the material underneath at the time ofapplication of suction. I have discovered that even though the outer endis totally unsecured, the roll may be successfully picked up by asuction head means, without tearing the outer loop or wrapper orotherwise damaging the roll.

I have further discovered that even if the outer loop is loose or thewrapper is loose, if the application of suction is withheld until theouter loop or wrapper is pressed against the remainder, the roll can bepicked up, with the atmospheric pressure forming a pressure seal betweenthe roll and the sealing means of the suction head.

I have further discovered that with certain kinds of paper, when pickingup a roll of paper by a suction head means, there apparently issuificient air entrapped within the loops of the roll to puncture a loopor loops in the area of the suction head. I have further discovered thatif the area of the roll defined by the suction head means is preventedfrom movement away from the remainder, this puncturing can be prevented.

It is therefore an object of the present invention to provide a methodof picking up a roll of paper comprising creating a subatmosphericpressure over a selected area of the exterior surface of the roll, priorto creating the subatmospheric pressure, making certain that suchsurface is tightly against the underlying portions of the roll, andpreventing such exterior surface in the selected area from separatingmovement from such remainder.

In developing the method of the present invention, I have discovered anovel apparatus by which the method may be carried out, and have furtherdiscovered devices useful in lifting apparatus in general.

A main object of the invention is to provide a suction apparatus forpicking up a roll of paper or similarly shaped object.

A further object is to provide a suction lift apparatus having a novelload contacting means capable of adjusting to the contour of the objectto be picked up.

Another object is to provide a novel means of controlling the movementof a plurality of load contacting devices.

A further object is to provide a suction lift apparatus having novelvalve means for controlling the communication of the suction heads tothe source of vacuum.

Another object is to provide a suction lift attachment for an industriallift truck which is mounted for movement on the mast of the truck in anovel manner to facilitate more ready and proper contact between thesuction lift attachment and the roll.

Another object of the invention is to provide a suction lift attachmentfor an industrial lift truck which is mounted for rotary movement abouta longitudinal axis so as to up end a roll.

Another object of the invention is to provide a novel sealing means fora suction vacuum head.

Various other objects of the invention will be apparent from thefollowing description taken in connection with the accompanyingdrawings, wherein:

FIG- 1 is a side view in elevation of a lift truck showing indiagrammatic form an attachment of the present invention;

FIG. 2 is a plan view of the structure disclosed in FIG. 1;

FIG. 3 is. a side view in elevation showing the roll attachment ashaving been rotated degrees in position for picking up. a roll in ahorizontal position;

FIG. 4 is a front view of the suction apparatus but being much lessdiagrammatic than FIGS. 1, 2 and 3', parts being broken away forconvenience in illustration;

FIG. 5 is a plan view of the attachment of FIG. 4, parts being brokenaway and other portions being shown in section, for instance, on line5--5 of FIG. 4 to show the manner of mounting. certain suction heads;

FIG. 5a is a sectional view taken along line 5a--5a of FIG. 5;

FIG. 6 is an enlarged vertical section taken along line 66 of FIG. 4;

FIG. 7 is an enlarged sectional view along line 7-7 of FIG. 4;

FIG. 8 is a side view of the structure shown in FIG. 4;

FIG. 9 is a sectional view taken along line 99 of FIG. 8;

FIG. 10 is a front elevational view of suction head 41;

FIG. 11 is a vertical section taken along line 1111 of FIG. 10;

FIG. 12 is a horizontal section taken along line 12-12 of FIG. 11;

FIG. 13 is a horizontal section taken along line 1313 of FIG. 10;

FIG. 14 is a sectional view taken along line 14-14 of FIG. 13;

FIG. 15 is a sectional view taken along line 15-15 of FIG. 10;

FIG. 16 is a schematic view of part of the suction system for thesuction head;

FIG. 17 is a diagrammatic view of a modified form of suction system forthe heads;

FIG. 18 shows another modified form of suction system for the head;

FIG. 19 is a vertical section through one of the apron valves;

FIG. 20 is an end view of the valve of FIG. 19;

FIG. 21 is a view similar to FIG. 19 but showing the valve unit ashaving been shifted to a second position;

FIG. 22 is a midsection through a modified form of valve;

FIG. 23 shows the same valve in a ditferent operative position;

FIG. 24 shows the valve in a subsequent stage of operation;

FIG. 25 is a sectional view taken along line 25-25 of FIG. 22;

FIG. 26 is a diagrammatic view of part of the hydraulic circuit for theattachment; FIG. 27 shows the head plate of one suction section in itsoperative position in contact with a roll; and

FIG. 28 is a diagrammatic view showing the suction heads against a rollhaving a loose end.

GENERAL DESCRIPTION Referring to the drawings and particularly to FIGS.1 and 2, the lift truck 21 has a mast 23 at the front end. A loadcarriage of the present invention is mounted by rollers 25 in the mastfor movement therealong under the influence of a lift mechanism, such asa hydraulic ram 27 shown in FIG. 2.

The load carriage includes as primary elements a carriage unit 31 havingthe rollers 25, a base member 33 mounted on the carriage for limitedpivotal movement by a connection 34, a revolving apron 35 rotatablymounted on the base member, and a plurality of suction heads, two pairsbeing shown and numbered 37 and 39 and 41 and 43 (FIG. 2). The heads aremounted on the apron, in a manner to be presently described, foradjustable movement of various types for proper engagement with a paperroll R.

If the roll to be picked up is in a horizontal position as shown in FIG.3, the suction heads can be rotated 90 degrees to adapt them for properengagement with the roll. It is also obvious that a roll picked up in avertical position of FIG. 1 can be revolved to the horizontal positionof FIG. 3 for deposit in a horizontal position if desired. The device ofthe present invention has specific features to facilitate proper supportof a roll by the suction heads when the roll is rotated.

Referring to FIG. 1, the suction heads 37-43 are connected to a sourceof suction on the truck body, such as a vacuum pump 51, by a hose orconduit 53. The hose 53 extends from the pump forwardly past a controlvalve 55, and then over a slack take-up sheave 57 mounted on the innermovable uprights of the mast, and then extends downwardly and throughthe rotary connection between the base member 33 and the apron 35. Amanifold arrangement connects the hose to the suction heads.

In operation, as the heads are brought into engagement with a roll, thevalve 55 is operated to connect the suction heads to the suction pump 51so that atmospheric pressure forces the roll against the heads withsufiicient force to enable the carriage to be elevated to lift the roll.

SPECIFIC DESCRIPTION Base Member Mounting Referring to FIGS. 5, a and 8the connection 34 is at the upper portion of the'base member 33 (FIG. 8)which comprises a flat circular plate (barely visible in FIG. 8).

The connection 34 comprises a universal joint having a socket member 101(FIG. 5a) carried by a lug 103 provided on the rear of the base member33 (FIG. 5). The socket member has a ball member bored to receive a pin109, the ends of the latter fitting in holes in a clevis fixed to theupper end of a cross piece 111 of the carriage unit 31. The spacesbetween the clevis and the lug allow for pivotal movement of the basemember relative to the carriage unit about a vertical axis. A pair oflaterally spaced stop elements 115 (FIG. 5) adjustably thread into thecarriage unit and limit such pivotal movement.

The base member can also pivot rearwardly on the connection 34.Referring to FIGS. 1, 8 and 9, to control such pivotal movement there isprovided a pair of spring assemblies, each including a compressionspring 119 surrounding telescoped elements 121 and 123 pivotallyconnected at 125 to the base member 33 and at 127 to the carriage unit31, respectively. The springs make a small acute angle With thevertical. Hence, the springs are compressed only slightly by substantialrearward movement of the lower portion of the base member. Thus, whilerearward movement of the lower portion of the base member is resisted bythe springs, it takes only a relatively small increase in force to somove the base member because of the angular relationship of the parts.

Referring to FIGS. 5, 8 and 9, at the bottom of the base member 33 thereis a link 129 pivotally connected at 131 to the base member and at 133to the carriage unit. The link is operable to prevent turning movementof the base member 33 about an axis extending longitudinally of thetruck.

Apron Mounting The apron 35 essentially comprises a generally flatgenerally rectangular plate having a revolving connection between theapron and the base member 33, which connection in FIGS. 1 and 2 is shownin diagrammatic form. In practice, the connection is generally like thatshown in the Ehmann Patent 2,959,131. Thus, referring to FIGS. 5 and 8of the present application, there is an annular row of bearings 135between the base member 33 and an annular flange 139 on the apron 35.Referring now to FIGS. 5, 6 and 8, a pair of cylinders 141 fixed on thebase member have pistons 142 equipped with rack teeth to drive a pinion143. The pinion is secured by bolts 145 to the apron 35. Suitablehousing members 147 (FIG. 5) are provided for the ends of the cylinders141.

The hydraulic conduits or hoses between the truck and the cylinders 141are not shown, but may be of conventional form. These hoses extend fromthe truck over suitable slack take-up devices, not shown, and then leadto the carriage unit and connect to suitable fittings (not shown)mounted on the carriage unit 31. Short hose sections (not shown) extendfrom the fittings to the cylinders 141.

Suction Head Mounting The mounting of each pair of suction heads is thesame, and so only one mounting will be described. Referring to FIGS. 5and 11, the heads 41 and 43 each includes an elongated, rigid base platemember 161 (FIG. 11) having clevis lugs 163 at the upper and lowerportions connected by pivot pins 165 (FIG. 5) to the opposite ends of apair of mounting links 167. Each link is pivotally mounted at itscentral portion by a pin 169 to a pair of clevis lugs 171 fixed to thefront of the apron 35, or fixed to a detachably mounted plate orbracket, not shown, if desired.

As best shown in FIG. 5, each end of each mounting link has a flat frontend edge 181 angularly intersecting a flat front intermediate edge 183.As the head 43 is shown in FIG. 5, the edge 181 is disposed next to theplate member 161 of the head and intersects the edge 183 at a place sothat the head 43 may pivot from the position shown a limited extent in aclockwise direction relative to the associated links. The edges 181 and183 thus limit pivotal movement of the head relative to the links, butthe absolute pivotal movement of the heads is greater and includes thepivotal movement of the mounting links themselves.

As the head 41 is shown in FIG. 5, the edge 183 is disposed next to theplate member of the head, and thus the head 39 may pivot a limitedextent in a clockwise direction. The angular movement of the heads 41and 43 relative to the links, in the particular embodiment of theinvention shown, is in the order of 20 to 25 degrees.

Hydraulic Control System for Suction Heads A hydraulic circuit isprovided in association with the mounting links to control their pivotalmovement. Referring to FIGS. 5 and 26, the circuit includes a cylinder201 for each link 167 pivotally mounted on the clevis 171 by a pin 203as shown in FIGS. 4 and 5. The cylinder has a piston 205 (FIG. 26)equipped with a rod 207 having a sleeve 209 (FIG. 4) receiving the pivotpin 165, previously mentioned.

Referring to FIG. 26 each cylinder has its rod end hydraulicallyconnected by a separate line 211 to an intermediate portion of aseparate passage 213 in the valve body 214 of a check valve unit. Thebody is mounted on the apron 35 (FIG. 4) and includes a pair of checkvalves 215 and 217 (FIG. 26) for each passage 213. The check valves aredisposed on the opposite sides of the lines 211 and open in the samedirection. A common line 219 connects all the check valves 215 to anaccumulator 221 mounted on the apron 35 (FIG. 4), and a common line 223connects all the check valves to a solenoid valve 225 also mounted onthe apron (FIG. 4). The solenoid valve is connected to the line 219 by aline 227.

Referring to FIGS. 4, 6 and 26, there is a vacuumoperated switch 231mounted on a hollow suction T 233 (FIG. 6) and connected by a conductor235 (FIG. 26) to the solenoid valve 225. The switch 231 is grounded onthe apron 35, and a live conductor 237a (FIG. 6) connects the valve 225to a terminal 239 on the T 233. A conductor 23711 is connected to theterminal and extends through the suction conduit 53 to a terminal 241 onthe trucks. A conductor 237a connects terminal 241 to the battery 243(FIG. 26) of the truck. The conductors 237a, 237b and 2370 may beconsidered as constituting a single conductor 237.

The vacuum switch is responsive to a predetermined vacuum in the suctionT 233 to energize the solenoid valve and close off communication betweenthe lines 223 and 227. In one unit, the vacuum switch was responsive toa vacuum of seven inches of mercury to energize the solenoid valve.

Referring to FIGS. 5 and 26, in operation, the accumulator 221 createssufficient pressure in the line 219 to dispose the pistons 205 remotelyfrom the inner ends of their cylinders to yieldingly constrain the links167 to assume positions with their heads in relatively closed positionsrather than in open positions. That is, the heads are constrained toface more inwardly toward a central point, rather than face forwardly.

If it is assumed that the heads engage a roll of large diameter, largerthan the diameter of the are along which the heads are disposed, theouter heads 37 and 43 will be first engaged and shoved rearwardly thuspivoting the mounting links 167 to swing the inner heads 39 and 41forwardly for proper engagement with the roll. This pivoting movement ofthe links 167 will move the pistons 205 inwardly, as the parts are shownin FIG. 26. Fluid is prevented by the check valves 215 from flowing fromthe pistons directly into the line 219, but check valves 217 permit thefluid to flow into the line 223 from whence it floyv s through the valve225 and line 227 to line 219 and thence to the accumulator 221.

Assuming that the valve 55 (FIG. 1) is open so that the suction headsare connected to the vacuum pump 51, a drop in pressure will occur atthe heads soon after they contact a load. This drop will shortly besuflicient to actuate the vacuum switch 231 (FIG. 26) to close valve225. Thus, further opening movement of the heads is prohibited. Thereason for locking the heads against opening movement is to hold theheads firmly in place to support the roll when the apron 35 is rotatedto a position with the roll axis horizontal, or if the roll is alreadyhorizontal, to enable the heads to support the roll when the carriage islifted.

It is pointed out, however, that even after the valve 225 has closed,links 167 may pivot in directions to further close the heads, such asfor instance, when a small roll is being lifted and the vacuum switch231 has been operated prior to the time the heads have conformed to thecontour of the roll. This movement of the links 167 may take placebecause fluid can flow from the accumulator 221, through line 219,through check valves 215 into the inner ends of the cylinders. Suchfluid flow enables the mentioned movement of the links 167.

Overall Suction System Referring to FIG. l'the suction hose 53 leadsfrom the truck over the sheave 57 and down to a tube 251 (FIG. 6)mounted by a support strip 255, on the cylinders 141. The tube 251extends through a bore in the pinion gear 143 and has a rotary slidingfit in the leg of the suction T 233. An O-ring 257 provides a sealbetween these parts.

The suction T 233 is secured by a mounting strip 261 (FIGS. 4 and 7) tothe revolving apron 35, and the arms of the T are connected by hoses 263and 265, as shown in FIGS. 4 and 16, to the legs of a pair of T valves267 and 269 disposed above and below the apron respectively.

As shown in FIGS. 5 and 16, hoses 270 connect the arms of the valves 267and 269 to the inner arms of suction Ts 271, the legs of which aresecured to the base plates 161 (FIG. 11) of the inner suction heads.Hoses 273 (FIG. 16) connect the remaining arms of the Ts 271 to nipples275 on the base plates 161 (FIG. 5) of the outer suction heads.

Suction Head Construction Referring to FIGS. 10 through 15, each suctionhead is provided with an elastomer sealing member 281 of openrectangular form (FIG. 10) secured by strips 282 (FIG. 11) to the edgesof the base plate 161. The sealing member is molded on its inner surfacewith a groove 283 to receive the edge of the base plate 161. Thus, thereis a lip 285 at the back of the base plate, and a lip 287 is at thefront. The lip 287 is hollow and thus has an outer Wall portion and aninner wall portion. The inner wall portion is thickened near the plate161 whereas the outer wall portion is not thickened at such place. Thethickened portion projects inwardly to constrain the lip 287, when inengagement with a load, to flex outwardly rather than inwardly. The lip287 may be provided with vents 288 to enable it to deflect more readily.

Two dams 291 form part of and extend between the sides of the sealingmember, and engage the load and separate the head into three suctionsections.

Each base plate 161 is provided on its rear face with an airtightmanifold member 301 of angular form secured at its ends to the adjacentclevis members 163. The manifold member communicates with ports 303, 305and 307 formed in the base plate 161 along the length thereof, so thatthe three suction sections of the head are in communication with oneanother.

On the front of the base plate 161 are three flexible roll engagingplates 311, 313 and 315 of rectangular shape. Each plate comprises ametal sheet 317 having an elastomer sheet 319 bonded to the front facethereof. The elastomer sheet 3 19 has a front face of generally wafileform for proper communication of the various parts of the face platewith the source of vacuum. Each plate is provided with a plurality ofair ports 321, three being shown.

Suction Plate Mounting Each plate is mounted in the same manner, and themounting arrangement comprises two pairs of rocker elements 333 (FIGS.11 and 15) of half round cross section secured to the plate by screws335. The elements of each pair are in longitudinal alignment with oneanother and in spaced endwise relation. The round portions of the rockerelements are designed to bear against the front of the base plates 161.

The rockers are held in contiguous relation to the base plate by aT-shaped retainer having a threaded shank 337 (FIG. 14) passing throughthe base plate and secured by a nut 339 to such plate. The head 341 ofthe retainer is formed with a through oversize bore 343 looselyreceiving a pin 345, the ends of which have a drive fit in the adjacentends of the associated rocker elements. The head 341 has a peaked frontsurface 347 (FIG. 13) to facilitate flexing of the associated platewithout interference by the head.

The oversize bores 343 not only facilitate contact between the rockerelements 333 and the base plate, but also facilitate slight lateralmovement of the rocker elements which is necessary when the flexibleplate flexes, as can be appreciated by examining FIG. 15.

Automatic Suction Valves Referring to FIGS. 19 and 20, the arm portions269' and 269" of the valve 269 are each provided interiorly with a valveseat 361 and a movable valve element 363 for each seat. A rod 365secures the valve elements to one another in the desired spacedrelationship. The valve elements and the rods may be considered as avalve unit. A light compression spring 367 engages a scalloped flange369 of each valve element and disposes the valve unit in a centeredposition with both valve elements spaced from their seats. Each valveelement has a small passage or orifice 371 formed therethrough.

While the overall operation of the roll pick-up device will be givenshortly, the operation of the above valve will be given here.

If it is assumed that the pick-up device is ap roaching a roll, thesprings 367 will hold the valve unit in it centered position whether ornot the control valve 55 isolates or connects the leg 269" of the valveto the vacuum pump. If a suction head to which the arm 269" is connectedengages a load (FIG. 21) the pressure in the right-hand end of the armwill drop substantially below atmospheric pressure. If the suction headto which the left-hand arm 269 is connected is not against the load or aload, the pressure in the left-hand arm will remain substantiallyatmospheric. This difference in pressure acts on the valve unit to forceit to the right to seat the left-hand valve element 363 (FIG. 21) andfurther unseat the right-hand valve element 363. This substantiallydecreases the loss of vacuum, and facilitates the use of a smallercapacity vacuum pump than Would otherwise be the case. More importantly,the valve permits the device to pick up a load which covers only part ofthe area of the overall} suction means, by automatically closing off anyvacuum head not covered by an article to be lifted.

Should the head to which the left-hand arm 269' is connectedsubsequently engage the load or a load, the air in the left-hand end ofthe arm will be drawn through the passage 371 to drop the pressure insuch end. This drop in pressure lessens the differential pressure acrossthe valve unit, so that the centering springs 367 can again center thevalve unit so that both valve elements are unseated. This provides foropen communication between the suction heads and the vacuum pump.

FIGS. 22 through 25 show a modified form of automatic valve forattachment to a single head. The tubular body 381 has a shoulder 383providing a valve seat against which a valve element 385 may seat. Asingle compression spring 386 bears against a scalloped flange 387 onthe valve element, and a snap ring 389 limits movement of the valveelement to the left. The valve element is formed with a through smallpassage or orifice 391.

If it is assumed that the right-hand end of the body 381 is connected toa source of vacuum, and the left-hand end to a suction head, the springwill dispose the valve ele ment in an open position when the vacuum isoff. When the vacuum is on as in FIG. 23 a differential pressure acrossthe valve element is created, so that the valve element closes againstthe seat.

Now, if the suction head which is connected to the left-hand end of thevalve body is disposed against a load, there will be a pressure drop inthe left-hand end of the body because of the passage 391, to therebylessen the differential pressure across the valve element suflicientlyto enable the spring to open or unseat the valve element for bettercommunication of the suction head with the pump.

OVERALL OPERATION Let it be assumed that the roll to be picked up is ina vertical position as shown in FIGS. 1 and 2, and that it is ofsubstantial diameter, that is having a diameter such that it will firstengage the outer heads 37 and 43. The operator will drive the truck upto the roll, attempting to center the truck on the roll. However, exactcentering is not required since the base member 33 can pivot about theconnection 34 to center the heads with respect to the roll.

Prior to or at about the time the heads engage the roll, the operatoropens the valve 55, and suction i available at the heads because theapron valves 267 and 269 (FIG. 19) are open (there being as yet nodifferential pressure across the valve units of the valves).

Contact of the heads with the roll will swing and pivot the heads topositions conforming the positions of the heads to the curvature of theroll, bodily swinging movement of heads being permitted by the openvalve 225 (FIG. 26).

The contact between the heads and the roll shortly creates a pressuredrop at the heads and at the vacuum switch 231 to lock the heads againstfurther opening movement. Normally, the locking of the heads occursafter the heads have fully conformed to the contour of the roll.

Although the outer heads 37 and 43 first contact the roll, this will notatfect the apron valves 267 and 269 because, by reference to FIG. 16, itis apparent that there is still no differential pressure across theapron valves.

As the pressure at the heads continues to drop, the atmospheric pressureon the opposite side of the roll forces the heads and roll together withsuflicient pressure of contact to deflect the head plates 311, 313 and315 into conforming relationship to the roll, as shown in the case ofplate 311 in FIG. 27 and with suflicient pressure to enable the roll tobe lifted. Also, the sealing member 281 is deformed outwardly to createa good seal with the roll.

Paper such as newsprint or kraft paper or the like is permeable to thepassage of air therethrough, at least to a limited extent. Thus thecreation of a subatrnospheric pressure on a selected area of thecylindrcial surface of the roll will create a pressure gradient over thearea, wherein the pressure is lowest on the outer surface of theoutermost convolutions and increases in magnitude toward the center ofthe roll through successive convolutions. After the pressure gradient iscreated, the zone of subatmospheric pressure at this area may be movedto impart movement to the plurality of layers because of the pressuregradient and to impart movement to the remaining layers because of theirenclosure by the just-mentioned plurality of layers.

Now, the roll may be picked up by elevating the load carriage, and theroll may be rotated to the horizontal position if desired for properdisposition for use or storage. In such horizontal position, the pins345 and the retainers 337, 341 support the head plates 311, 313

and 315 against downward shifting movement. It is pointed out that thepressure of contact between the roll and head plates must be suflicientto create a frictional force between the roll and the head platesgreater than the weight of the roll. However, the roll is not picked upbecause of adherence of the suction heads to the outer loop of paper onthe roll, but because the roll is being pressed against the heads by thedifferential pressure across the roll created by the suction heads.Thus, by reference to FIG. 28, a roll having an unattached outer loop Lmay be picked up, providing the outer loop is pressed tightly againstthe remainder of the roll prior to the suction heads being connected tothe vacuum pump.

Referring to FIG. 3, a roll in a hozontal position may be picked up byrotating the apron to dispose the heads as shown and locating carriageso that the lower pair of heads, 37 and 39, is at the approximate centerof the roll. When the truck is now further advanced toward the roll,heads 37 and 39 contact the roll at which point, the operator lowers theapron while still advancing the truck. The frictional force between theheads 37 and 39 impart a counterclockwise rotation to the roll (asviewed in FIG. 3) which compensates for the usual tendency of the rollfor rolling away from the truck. It is understood that, at thisjuncture, the vacuum has not yet been applied. To compensate foroperator errors, the attachment can pivot slightly around pin 109 (FIG.8) as controlled by springs 119.

Instead of lifting a large roll, two small rolls may be lifted by thesuction heads, or a single small roll may be lifted by one pair ofheads, such as for instance, heads 37 and 39. Under the lattercircumstance, the heads 41 .and 43 will be open to the atmosphere.Referring to FIG. 16, it is apparent that a lower pressure will exist inthe suction lines to the left of the apron valves 267 and 269 than inthe lines to the right. The differential pressure across the valve unitof each valve (FIG. 19) will cause a shifting of the valve units to theleft to close off communication of the heads 41 and 43 with the vacuumpump.

Instead of a roll, a fiat faced package could also be readily picked up,with the heads pivoting to the proper positions for flush contact.

MODIFIED FORMS FIG. 17 shows the suction heads connected by a modifiedmanifold system, which facilitates cutting off vacuum to varioussuchtion sections of the head to facilitate lifting a short roll, or ashort load or package, in the event the heads lie in a common plane, orif there is only one suction head divided into twelve suction sections(or other even number of sections).

There is a central apron valve 401 between the valves 267a and 260a. Aleft apron valve 403 is connected by a line 405 to the central apronvalve 267a and by lines 407 to suction sections 37a and 39a, and bylines 409 to suction sections 37b and 3%.

There is a right-hand apron valve 411 conected by a line 412 to thecentral apron valve 269a and by lines 413 to suction sections 41b and43b and by lines 415 to suction sections 410 and 43c. A line 417connects apron valve 269:: to suction sections 370 and 39a, and a line41? connects apron valve 269a to suction sections 41a and 43a. As a sidenote, the dams 291 (FIG. 11) isolate the suction sections from oneanother, and no rear manifolds such as 301 are employed in the FIG. 17construction.

Let it be assumed that a load contacts the b and c sections but does notfully contact the a sections. A differential pressure is created acrossvalve 403 to close lines 407 and isolate 37a and 39a from the source ofvacuum. This situation also means that there will be a differentialpressure across valve 267a to close off line 419 and heads 41a and 43afrom the source of vacuum.

10 There will be low pressure on both sides of apron valve 401 so itremains open to both of its lines. Thus, only the suction sections incontact with the load are connected to the source of vacuum.

Assume, now, that the load contacts only the 37 and 39 sections. Thevalves 267a and 26% function to cut off vacuum from the 41 and 43sections. Suppose the load contacts only sections 37b, 39b, 37c and 39c.Valve 269a will cut off sections 41b, 43b, 41c and 430. Valve 403 willcut off sections 37a and 39a, and valve 267a will cut off sections 4111and 43a. Thus only the sections which fully contact the load aresupplied with suction.

Now suppose only sections 370 and 39c contact the load. Valve 269a willcut off sections 41b, 41c, 43b and 430. There will be no pressuredifferential across the valve 267a because its sections are all open tothe atmosphere. However, there will be a differential across valve 401,which will act to close off all the sections associated with valve 267a.Thus, again, only the sections fully contacting the load are suppliedwith suction.

Referring to FIG. 18, the suction sections of the heads 437 and 439 eachhas a valve 381 of the type shown in FIG. 22. Thus, only the sectionsthat are fully contacted will be supplied with suction. A differencebetween the FIG. 17 and the FIG. 18 arrangements, is that if only asingle section in FIG. 17 fully engages the load, suction will also besupplied to its companion section, while in FIG. 18 only the sectionengaging the load would be supplied with suction.

Having described the invention in what is considered to be the preferredembodiment thereof, it is desired that it be understood that theinvention is not to be limited other than by the provisions of thefollowing claims.

I claim:

1. A suction head comprising a base member, a sealing member on saidmember defining at least one encircled area, a plate-like load engagingmember separate from said sealing member and disposed within said areaand mounted on said base member, said member being flexible to tend toconform to the shape of the load engaged, said member being of a size tosubstantially fill said area.

2. In a suction type load pick-up device,

a plurality of suction elements for engaging a load,

a source of vacuum for said elements,

a separate valve means between each element and said source,

each valve means including a housing and a movable valve element in saidhousing movable toward and away from a seat in said housing, each valvemember having a seating surface facing the associated seat,

each valve member being slidably supported in its housing forrectilinear movement toward and away from said seat, to maintain saidseating surface facing said seat, each valve member having a shoulder,and a compression spring for each valve member, each spring beingdisposed between the shoulder of its valve member and an opposed portionof its housing and urging its valve member away from its seat,

each valve member being operable to seat against its seat in response tothe influence of a predetermined differential pressure thereacross,

each valve member being formed so as to provide substantial air passagesbetween itself and said housing for ready passage of fluid therepast,

each valve member having a leakage passage formed therethrough so that asuction may be created on the side of said valve member remote from thesource of vacuum despite the valve member being closed.

3. In a suction type load pick up device,

at least two suction heads,

a common valve for controlling the communication of said heads with asource of vacuum,

said valve having two seats, one for each head,

said valve having a valve member engageable with one seat when saidmember is moved to one position and engageable with the other seat whenmoved to another position and engageable with neither seat when 5 in anintermediate position,

and means urging said valve member to assume its intermediate positionbut being sufficiently sensitive to allow said valve member to shiftunder the influence of differential air pressure thereacross, said 10member being so located relative to said heads and said source that whenone head only engages a load, a dilferential pressure will be createdacross said valve member to shift it in a direction to close offcommunication of the other head with the source of 15 vacuum.

References Cited in the file of this patent UNITED STATES PATENTSHitchcock Feb. 11, 1919 Debaecker Aug. 19, 1924 Lente Apr. 25, 1944Billner Dec. 11, 1951 Frischmann et al May 13, 1952 Frischmann July 22,1952 Sherrifl July 13, 1954 Littell June 9, 1959 Cushman July 7, 1959Corbin Aug. 11, 1959 Morris et al. Sept. 8, 1959 Cotesworth et al Dec.1, 1959 Horton June 28, 1960 Leighton Nov. 28, 1961

1. A SUCTION HEAD COMPRISING A BASE MEMBER, A SEALING MEMBER ON SAIDMEMBER DEFINING AT LEAST ONE ENCIRCLED AREA, A PLATE-LIKE LOAD ENGAGINGMEMBER SEPARATE FROM SAID SEALING MEMBER AND DISPOSED WITHIN SAID AREAAND MOUNTED ON SAID BASE MEMBER, SAID MEMBER BEING FLEXIBLE TO TEND TOCONFORM TO THE SHAPE OF THE LOAD ENGAGED, SAID MEMBER BEING OF A SIZE TOSUBSTANTIALLY FILL SAID AREA.